J. Phys. IV France 113 (2004) 3
Effect of Merocyanine 540 on Langmuir-Blodgett films and liposomes of zwitterionic, anionic and cationic lipid compositionM. Alay, J. Prat, M.A. Alsina and M.A. Busquets
Physical Chemistry Department, Faculty of Pharmacy, Av. Joan XXIII, s/n, 08028 Barcelona, Spain
The interaction of the anionic probe Merocyanine 540 (MC540) with mono and bilayers of different lipid composition has been analyzed in order to get insight in the lipid charge influence on probe activity. The Langmuir-Blodgett technique showed that MC540 was able to incorporate predominantly into cationic lipid monolayers composed of Dimyristoyl phosphatidyl choline/Dimyristoyl trimethyl ammonium-propane (DMPC/DMPTAP) (75:25, mol:mol). However, at low surface pressures, the probe could also allocate into the interface of the zwitterionic Dimyristoyl phosphatidyl choline (DMPC) and the anionic Dimyristoyl phosphatidyl choline/ Dimyristoyl phosphatidyl glycerol (DMPCI/DMPG) (75:25, mol:mol) thus indicating a low interaction with these lipid compositions. These results were in agreement with the studies performed with Large Unilamelar Vesicles (LUVs) of the Same lipid compositions based in the spectroscopic analysis of probe absorption maxima modification upon its incorporation into the lipid bilayers.
© EDP Sciences 2004